The present invention relates to a brake actuation unit for actuating a ‘brake-by-wire’ type brake system for a motor vehicle comprising:                a brake booster operable both by means of a brake pedal mounted on a shaft and by means of an electronic control unit depending on the driver's request, with means being provided to decouple a force-transmitting connection between the brake pedal and the brake booster in the ‘brake-by-wire’ operating mode,        means to detect a deceleration request of the driver,        as well as a pedal travel simulator which interacts with the brake pedal and allows a resetting force acting on the brake pedal to be simulated in the ‘brake-by-wire’ operating mode independently of the actuation of the brake booster, and which can be connected in the ‘brake-by-wire’ operating mode when the force-transmitting connection between the brake pedal and the brake booster is decoupled and can be disconnected outside the ‘brake-by-wire’ operating mode, with the pedal travel simulator being formed of a simulator spring, which is arranged in terms of effect between a force-transmitting part connected to the brake pedal and a simulator housing which is mounted on the shaft by means of two bearings.        
An actuation unit of this type is disclosed in DE 10 2005 049 394 A1. In order to impart a known brake pedal feel to the operator, the prior art actuation unit provides a simulator spring, which is configured as a flat bending spring. Means to produce a hysteresis are provided in addition. However, the mentioned publication does not allow taking any hints as to the mounting support of the simulator housing on the shaft of the brake pedal. It is feasible in a design of the pedal travel simulator, which basically comprises one simulator housing and two housing covers that close the housing, to arrange the bearings in the two simulator housing covers respectively, i.e. in two different components. Tension is encountered at the bearings and in the overall pedal travel simulator on account of manufacturing tolerances and variations in the positioning of the relevant parts.
In view of the above, an object of the invention is to further develop an actuation unit of the type mentioned hereinabove, wherein the forces that develop upon actuation of the pedal travel simulator can be reduced to a large extent. Another objective is to reduce the number of component parts required for the simulator housing.